If we know that n+2 is a multiple of 3, how would we know that n-4, n-1, and n+5 are also multiples of 3? What math are you doing to get those answers? What is your thinking? Where do you start?
Hi aces021,
To help you with this concept, you should think about how a number line "works":
Let's start with a consecutive series of numbers.....
1 2 3 4 5 6 7 8 9 10 11 12 etc.
When we're told that (N+2) is a multiple of 3, then we have to start with 3 or 6 or 9 etc.
Now, let's say that (N+2) = 9....what OTHER values do we know would also be multiples of 3?
If we go "up", then the next multiple is 12.....that would be 3 more than (N+2), so (N+5) is a multiple of 3.
If we go "down", then the next multiple is 6....the would be 3 less than (N+2), so (N-1) is a multiple of 3.
If we go "down" again, then the next multiple is 3...the would be 3 less than (N-1), so (N-4) is a multiple of 3.
Etc.
GMAT assassins aren't born, they're made,
Rich
